US6191576B1 - Method of operating or constructing a geartooth sensor - Google Patents

Method of operating or constructing a geartooth sensor Download PDF

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Publication number
US6191576B1
US6191576B1 US09/107,798 US10779898A US6191576B1 US 6191576 B1 US6191576 B1 US 6191576B1 US 10779898 A US10779898 A US 10779898A US 6191576 B1 US6191576 B1 US 6191576B1
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Prior art keywords
peak
sensor
output
geartooth
operating
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US09/107,798
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Lamar F. Ricks
Wayne A. Lamb
Peter G. Hancock
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Honeywell Inc
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Honeywell Inc
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Assigned to HONEYWELL INC. reassignment HONEYWELL INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: LAMB, WAYNE A., RICKS, LAMAR F., HANCOCK, PETER G.
Priority to PCT/US1999/014875 priority patent/WO2000000791A1/en
Priority to JP2000557114A priority patent/JP2002519654A/ja
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Assigned to THE UNITED STATES GOVERNMENT reassignment THE UNITED STATES GOVERNMENT CONFIRMATORY LICENSE FOR GOVERNMENT REGISTER Assignors: ROCKEFELLER UNIVERSITY
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
    • G01D5/244—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing characteristics of pulses or pulse trains; generating pulses or pulse trains
    • G01D5/24471—Error correction
    • G01D5/24476—Signal processing
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D3/00—Indicating or recording apparatus with provision for the special purposes referred to in the subgroups
    • G01D3/02—Indicating or recording apparatus with provision for the special purposes referred to in the subgroups with provision for altering or correcting the law of variation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
    • G01D5/244—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing characteristics of pulses or pulse trains; generating pulses or pulse trains
    • G01D5/24471—Error correction
    • G01D5/2448—Correction of gain, threshold, offset or phase control

Definitions

  • the present invention relates generally to position sensing apparatus and more particularly to magnetic effect sensing apparatus including linear position sensing as well as the commonly known rotary position “geartooth sensors” wherein a magnetically sensitive device senses a ferrous object or objects generally projecting from a rotating target and resembling the teeth of a gear.
  • sensors are known in the magnetic effect sensing arts. Examples of common magnetic effect sensors may include Hall effect and magnetoresistive technologies. Generally described, these magnetic sensors will respond to the change of magnetic field as influenced by the presence or absence of a ferromagnetic target object of a designed shape passing by the sensory field of the magnetic effect sensor. The sensor will then give an electrical output which can be further modified as necessary by subsequent electronics to yield sensing and control information. The subsequent electronics may be either onboard or outboard of the sensor package ital.
  • geartooth sensors are known in the automotive arts to provide information to an engine controller for efficient operation of the internal combustion engine.
  • One such known arrangement involves the placing of a ferrous target wheel on the crank shaft of the engine with the sensor located proximate thereto.
  • the target objects, or features, i.e. tooth and slot, are of course properly keyed to mechanical operation of engine components.
  • the waveforms produced by the magnetic sensor change in response to varying airgap between the target and sensor faces.
  • differences among the biasing magnets used in the magnetic sensor, temperature, mechanical stresses, irregular target feature spacing, etc. can vary the sensor output. Therefore, the point at which the sensor changes state, i.e. the switch point, varies in time, or drifts, in relation to the degree of rotation of the target.
  • the mechanical action of the engine as represented by the target does not change. That is, there is a “true point” on the target in angle, or degrees of rotation, related to a hard-edge transition, which represents the point at which the sensor should change state to indicate a mechanical function of the engine.
  • an adaptive threshold includes setting the adaptive threshold at a fixed level above a measured minimum magnetic bias signal.
  • this function does not convey information proportional to air gap, therefore high accuracy is not achievable.
  • Another method is setting the threshold at the average value of magnetic bias by using a time based integrator such as an RC circuit. While this method can yield high accuracy, the accuracy is not achieved until considerable amount of target rotation has taken place. It is more desirable to achieve the adaptive threshold point very quickly in the target rotation.
  • the present invention discloses a method for operating a geartooth sensor.
  • the present invention discloses a method for constructing a geartooth sensing system.
  • An empirically derived first constant (M1) is derived to account for anticipated output voltage fluctuations inherent in the target and the anticipated airgap tolerance range.
  • the M1 constant is applied to the measured peak value (B peak ) or values of selected waveforms to obtain a value B max. Using this value alone as the AT point eliminates the majority of drift in the sensor.
  • a second empirically derived constant (M 2 ) is derived and applied to a measured or time integrated average value (B avg ) of, e.g., each wave to obtain a low value (B min ).
  • the average value referred to may be either a calculated arithmetical value or a time based value taking the form of median or mean values.
  • B max and B min are then added to obtain the final adaptive threshold value (AT) which is up-dated at the sensor circuitry to eliminate another portion of drift and define accurate sensor output switch points.
  • M 1 and M 2 are empirically derived or modeled constants which are adapted to a specific target configuration and duty cycle as measured or modeled over the anticipated airgap tolerances of the specific application of the Hall sensor 11 with respect to target 13 .
  • the present invention synchronizes quickly while obtaining very good accuracy when the B min value is added at the slightly later time taken to acquire it.
  • the need for performing calibration on the sensor and, e.g. adjusting its circuitry by laser trimming or the like, to improve sensor accuracy is minimized.
  • the AT point is held in the sensor circuitry, whether analog or digital, and may be updated at any chosen frequency to minimize the drift of the sensor switch points, thereby minimizing sensor inaccuracy and increasing engine efficiency.
  • FIG. 1 is a block diagram schematic view of the sensor according to the present invention.
  • FIG. 2 illustrates a graph of plotted signal gauss waveforms (also referred to as magnetic transducer output waveforms) over a plurality of air gap distances between the sensor of the present invention and a rotating target.
  • a back biased Hall element sensor or the like 11 is placed in proximity to a ferrous geartooth target 13 .
  • the output of the Hall is then sent to an amplifier 15 which produces a characteristic waveform (FIG. 2) which is dependent largely upon the airgap between the Hall sensor and the target, and may be affected by temperature and bias magnet strength.
  • the amplified Hall output signal is then sent to measuring circuitry 17 to determine the peak (B peak ) of the waveforms.
  • the design of such circuitry is considered within the skill of the ordinary artisan and need not be elaborated here.
  • the amplified output is additionally sent to circuitry 19 to determine the average value (B avg ) of the waveforms at 19 .
  • this circuitry is considered a matter of choice within the art and need not be detailed.
  • the average could be an arithmetic calculation or derived from a time based integrator. It will of course be appreciated by the ordinarily skilled artisan that any variety of analog or digital implementation in hardware or software may be utilized to accomplish the electronic circuitry behind the Hall effect sensor.
  • the measured B peak value is then further processed at block 21 by applying a first constant M 1 to the peak value in order to establish the larger portion of the adaptive threshold which represents the majority of elimination of drift among the varying signals. As seen in FIG. 2, it is the peak 39 of the signal which varies most due to airgap variation while the minimum or bottom 41 of the waveform remains relatively constant.
  • the B avg value 19 is then sent to block 23 for applying a second constant M 2 to the average value to derive the value B-minimum.
  • M 1 and M 2 values could, e.g., be fixed on an IC resistive network by laser trimming.
  • the adaptive threshold is selected to most closely approximate a line of values through the various airgap influenced waveforms to yield a switch point least varying in degrees relative to target rotation.
  • M 1 and M 2 are constants which are derived from a specific target configuration and duty cycle over the anticipated airgap tolerances of the specific application of the Hall sensor 11 with respect to target 13 .
  • the M 1 constant is typically selected as a large percentage of the peak value B peak . This value, B peak , conveys the greatest amount of information about airgap. B peak is further the most quickly acquired value in the sensor circuitry, there being necessary only one tooth to pass the sensor in order to establish B peak .
  • Typical values could be, e.g., 0.7 to 0.9 for M 1 .
  • M 1 is selected to be a much lower value, for example, 0.5, which is then applied to the determined B avg , therefore yielding a much smaller number because M 1 is greater than M 2 and B peak is greater than B avg .
  • B avg is of course acquired later in time over several degrees of target rotation, i.e. the passage of a plurality of tooth and slot features on the target 13 .
  • the adaptive threshold value (AT) 27 is the point on each air gap variant of the waveform corresponding to the least amount of drift and the most accurate representation of target rotation switch point for the sensor change in output state.
  • the adaptive threshold (AT) is then applied to the sensor circuitry, as by comparison to actual sensor output represented by line 35 , which is also applied to the comparator 29 in order to yield the most accurate sensor output 31 .
  • AT adaptive threshold
  • B peak is measured maximum value of the waveform
  • B avg is measured average value of the waveform
  • M 1 and M 2 are empirically derived constants applied to B peak and B avg , respectively, when taking into account the target design, duty cycle and expected waveform variations over a variety of operating conditions including expected airgap tolerance.
  • the present invention utilizes both B peak , which contains the most information about airgap variation signal effect, and B avg which contains duty cycle information and is a highly accurate indicator of waveform switch point drift, the sensor of the present invention yields a good balance of speed of adaptive threshold acquisition, overall accuracy, and averaging consistency since measurement is not necessarily required of every peak and valley excursion of the waveform. Further, because the present invention yields a highly accurate and adaptive threshold for the switch point, sensor calibration of individual sensors is not necessary during manufacture to yield predictable and accurate results.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Technology Law (AREA)
  • Signal Processing (AREA)
  • Transmission And Conversion Of Sensor Element Output (AREA)
US09/107,798 1998-06-30 1998-06-30 Method of operating or constructing a geartooth sensor Expired - Fee Related US6191576B1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US09/107,798 US6191576B1 (en) 1998-06-30 1998-06-30 Method of operating or constructing a geartooth sensor
PCT/US1999/014875 WO2000000791A1 (en) 1998-06-30 1999-06-29 Geartooth sensor signal processing using an adaptive threshold
JP2000557114A JP2002519654A (ja) 1998-06-30 1999-06-29 適応閾値を使用する歯車センサ信号処理

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US09/107,798 US6191576B1 (en) 1998-06-30 1998-06-30 Method of operating or constructing a geartooth sensor

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Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6636033B2 (en) * 2000-01-31 2003-10-21 Infineon Technologies Ag Sensor apparatus and method for generating an output signal of a sensor apparatus
US6727689B1 (en) * 2003-07-24 2004-04-27 Honeywell International Inc. Magnetic-effect sensing apparatus with signal thresholding
US20040095129A1 (en) * 2002-11-15 2004-05-20 Furlong Gregory R. Sensing methods and systems for hall and/or mr sensors
US6748007B1 (en) * 1999-06-02 2004-06-08 Commissariat A L'energie Atomique Method of processing a pulse response with an adaptive threshold and corresponding receiver
FR2853067A1 (fr) * 2003-03-31 2004-10-01 Denso Corp Procede de reglage de capteur magnetique, dispositif de reglage de capteur magnetique et capteur magnetique
US6806727B2 (en) 2000-06-26 2004-10-19 Snap-On Incorporated Alternator testing method and system using ripple detection
US20050035758A1 (en) * 2003-08-13 2005-02-17 Waszkowski Paul J. Vehicle direction detection using tone ring
US20050127685A1 (en) * 2003-12-03 2005-06-16 Honeywell International Inc. Latch control by gear position sensing
US20070090654A1 (en) * 2005-10-20 2007-04-26 Honeywell International Inc. System and method for registering the drive mechanism position of a latch apparatus after power loss
US20080000730A1 (en) * 2004-09-09 2008-01-03 Goodrich Actuation Systems Sas No-Back Device Having Malfunction Detection
US20080012354A1 (en) * 2006-05-26 2008-01-17 John Phillip Chevalier Latch control by gear position sensing
CN102841253A (zh) * 2011-06-21 2012-12-26 朋程科技股份有限公司 交流发电机的相位检测装置及其方法
US20130293221A1 (en) * 2012-05-07 2013-11-07 Razvan-Catalin Mialtu Output switching systems and methods for magnetic field sensors
US8723512B1 (en) * 2012-11-26 2014-05-13 Allegro Microsystems, Llc Circuits and methods for generating a threshold signal used in a magnetic field sensor based on a peak signal associated with a prior cycle of a magnetic field signal
CN104330583A (zh) * 2014-10-28 2015-02-04 陕西千山航空电子有限责任公司 一种航空发动机转速信号的采集电路
US9140536B2 (en) 2010-06-04 2015-09-22 Allegro Microsystems, Llc Circuits and methods using a first cycle of a signal to generate a threshold signal used for comparing to a second later cycle of the signal
US9476899B2 (en) 2013-08-30 2016-10-25 Allegro Microsystems, Llc Circuits and methods for generating a threshold signal used in a motion detector in accordance with a least common multiple of a set of possible quantities of features upon a target
EP2261680A3 (en) * 2002-02-05 2017-10-04 Allegro Microsystems, LLC Peak-to-peak signal detector
US10102992B2 (en) 2014-02-25 2018-10-16 Infineon Technologies Ag Switching apparatus, switching system and switching method
US10338642B2 (en) 2016-05-20 2019-07-02 Honeywell International Inc. Hall switch with adaptive threshold

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6833554B2 (ja) * 2017-02-17 2021-02-24 三菱パワー株式会社 出力予測装置、及びそれを備えた出力予測システム、発電システム並びに出力予測方法

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EP0844736A2 (en) 1996-11-25 1998-05-27 Sharp Kabushiki Kaisha Waveform-Shaping circuit and a data-transmitting apparatus using such a circuit

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EP0036950A1 (en) 1980-03-06 1981-10-07 R.J. Reynolds Tobacco Company Dynamic threshold detector
US5442283A (en) 1993-09-03 1995-08-15 Allegro Microsystems, Inc. Hall-voltage slope-activated sensor
US5500589A (en) 1995-01-18 1996-03-19 Honeywell Inc. Method for calibrating a sensor by moving a magnet while monitoring an output signal from a magnetically sensitive component
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EP0844736A2 (en) 1996-11-25 1998-05-27 Sharp Kabushiki Kaisha Waveform-Shaping circuit and a data-transmitting apparatus using such a circuit

Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6748007B1 (en) * 1999-06-02 2004-06-08 Commissariat A L'energie Atomique Method of processing a pulse response with an adaptive threshold and corresponding receiver
US6636033B2 (en) * 2000-01-31 2003-10-21 Infineon Technologies Ag Sensor apparatus and method for generating an output signal of a sensor apparatus
US6806727B2 (en) 2000-06-26 2004-10-19 Snap-On Incorporated Alternator testing method and system using ripple detection
EP2261680A3 (en) * 2002-02-05 2017-10-04 Allegro Microsystems, LLC Peak-to-peak signal detector
US20040095129A1 (en) * 2002-11-15 2004-05-20 Furlong Gregory R. Sensing methods and systems for hall and/or mr sensors
US6759843B2 (en) * 2002-11-15 2004-07-06 Honeywell International Inc. Sensing methods and systems for hall and/or MR sensors
FR2853067A1 (fr) * 2003-03-31 2004-10-01 Denso Corp Procede de reglage de capteur magnetique, dispositif de reglage de capteur magnetique et capteur magnetique
US6727689B1 (en) * 2003-07-24 2004-04-27 Honeywell International Inc. Magnetic-effect sensing apparatus with signal thresholding
US20050035758A1 (en) * 2003-08-13 2005-02-17 Waszkowski Paul J. Vehicle direction detection using tone ring
US7116096B2 (en) 2003-08-13 2006-10-03 Bendix Commercial Vehicle Systems Llc Vehicle direction detection using tone ring
US20050127685A1 (en) * 2003-12-03 2005-06-16 Honeywell International Inc. Latch control by gear position sensing
US20080000730A1 (en) * 2004-09-09 2008-01-03 Goodrich Actuation Systems Sas No-Back Device Having Malfunction Detection
US8146858B2 (en) * 2004-09-09 2012-04-03 Goodrich Actuation Systems Sas No-back device having malfunction detection
US20070090654A1 (en) * 2005-10-20 2007-04-26 Honeywell International Inc. System and method for registering the drive mechanism position of a latch apparatus after power loss
US20080012354A1 (en) * 2006-05-26 2008-01-17 John Phillip Chevalier Latch control by gear position sensing
US9140536B2 (en) 2010-06-04 2015-09-22 Allegro Microsystems, Llc Circuits and methods using a first cycle of a signal to generate a threshold signal used for comparing to a second later cycle of the signal
CN102841253A (zh) * 2011-06-21 2012-12-26 朋程科技股份有限公司 交流发电机的相位检测装置及其方法
US20130293221A1 (en) * 2012-05-07 2013-11-07 Razvan-Catalin Mialtu Output switching systems and methods for magnetic field sensors
US9638548B2 (en) * 2012-05-07 2017-05-02 Infineon Technologies Ag Output switching systems and methods for magnetic field sensors
US8723512B1 (en) * 2012-11-26 2014-05-13 Allegro Microsystems, Llc Circuits and methods for generating a threshold signal used in a magnetic field sensor based on a peak signal associated with a prior cycle of a magnetic field signal
US9476899B2 (en) 2013-08-30 2016-10-25 Allegro Microsystems, Llc Circuits and methods for generating a threshold signal used in a motion detector in accordance with a least common multiple of a set of possible quantities of features upon a target
US10102992B2 (en) 2014-02-25 2018-10-16 Infineon Technologies Ag Switching apparatus, switching system and switching method
CN104330583A (zh) * 2014-10-28 2015-02-04 陕西千山航空电子有限责任公司 一种航空发动机转速信号的采集电路
US10338642B2 (en) 2016-05-20 2019-07-02 Honeywell International Inc. Hall switch with adaptive threshold

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JP2002519654A (ja) 2002-07-02

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